Neuromedin U (NMU) is a physiologically active peptide having a function of suppressing food intake or boosting energy metabolism, increasing body temperature, reducing body weight, or the like, and is expected to be applied as an anti-obesity drug (Patent Literature 1 and Non Patent Literature 1). In addition, it recently becomes evident that neuromedin U is involved in the glucose homeostasis, and neuromedin U also receives attention as a pharmaceutical for treating diabetes (Non Patent Literature 2).
It is noted that the amidated C-terminal 7 residues (Phe1-Leu2-Phe3-Arg4-Pro5-Arg6-Asn7-NH2) of NMU, which has been identified from each animal, remain exactly the same in mammals and are believed to be important for the activation of type 1 and type 2 NMU receptors (NMUR1 and NMUR2). It is known that NMUR1 is mainly expressed at high level in the peripheral tissues (mainly, intestinal tract, lung, or the like) while NMUR2 is mainly expressed at high level in the central system (mainly, hypothalamic paraventricular nucleus). Due to this reason, a selective agonist is required for each of NMUR1 and NMUR2.
For example, in Non Patent Literature 3, 3-cyclohexylpropionyl-Leu2-Leu3-Dpr4-Pro5-Arg6-Asn7-NH2 (Dpr: 2,3-diaminopropionic acid) is disclosed as a peptide which selectively activates NMUR2.